Underwater dynamic polarization imaging without dependence on the background region.

Active-polarization imaging holds significant promise for achieving clear underwater vision. However, only static targets were considered in previous studies, and a background region was required for image restoration. To address these issues, this study proposes an underwater dynamic polarization imaging method based on image pyramid decomposition and reconstruction. During the decomposition process, the polarized image is downsampled to generate an image pyramid. Subsequently, the spatial distribution of the polarization characteristics of the backscattered light is reconstructed by upsampling, which recovered the clear scene. The proposed method avoids dependence on the background region and is suitable for moving targets with varying polarization properties. The experimental results demonstrate effective elimination of backscattered light while sufficiently preserving the target details. In particular, for dynamic targets, processing times that fulfill practical requirements and yield superior recovery effects are simultaneously obtained.

Correlating the Photovoltaic Performance and Stability of the All-Small-Molecule Organic Solar Cells to Their Intermixed Phases Determined by Concentration-Dependent Ultraviolet-Visible Absorption Spectroscopy.

In addition to the donor-acceptor nano phases, the intermixed phase within the organic blends is crucial for the photovoltaic performance and stability of the bulk-heterojunction organic solar cells (OSCs). Here, the intermixed phase of a representative M-PhS:BTP-eC9 all-small-molecule organic solar cell was investigated by a concentration-dependent ultraviolet-visible (UV-vis) absorption spectroscopy method, where a shift of the absorption maximum wavelength was measured for the acceptor component with the increase of the acceptor concentration. The blend ratios of the acceptor to the donor in the intermixed phase, corresponding to the critical concentration for the formation of the acceptor nanophase (CAP), were determined to be 0.35, 0.20, and 0.15 for the as-cast, thermal annealing (TA), and the combined TA and solvent vapor annealing films. These results indicated that M-PhS and BTP-eC9 are kinetically well intermixed during spin coating, whereas TA and the following solvent annealing promote the crystallization of BTP-eC9 molecules out of the intermixed phase. The photovoltaic performance of the M-PhS:BTP-eC9 cells with different blend ratios was investigated. The formation of the BTP-eC9 nano phase in the blend film leads to stable VOC and fast increased JSC, which can be understood by the reduction of bimolecular charge recombination and the formation of electron transporting pathways within the photoactive layer. Similarly, the critical concentration for the formation of the donor phase was estimated to be 0.15 by measuring the stabilized VOC and increased JSC values of the cells with different donor blending ratios. More importantly, after a fast "burn-in" thermal degradation, the M-PhS:BTP-eC9 cell showed excellent thermal stability aging at 85 °C for over 1128 h, which is in good accordance with the unchanged intermixed phases measured by the UV-vis spectra of the annealed films. The current work demonstrates the feasibility of the spectroscopy method to investigate the intermixed phases for organic bulk-heterojunction solar cells and proves that all-small-molecule solar cells can be intrinsically very stable.

Development of the Colorimetric and/or Fluorescent Probes for Detecting Fluoride ions in Aqueous Solution.

Fluoride ion is a strong Lewis base and one of the essential trace elements in human body. It plays a very important role in human health and ecological balance. The deficiency or excessive intake of fluoride ions will cause serious health problems, so the development of a sensitive and accurate detection method for fluoride ions is very important. The colorimetric and/or fluorescence sensing method has been a long standing attractive technique with high sensitivity and fast response. To date, most reported probes for fluoride ion are applicable only in organic solvents or organic-containing aqueous solutions. However, the probes for fluoride ion used in aqueous solution are more practically needed in view of environment protection and human health. In this paper, the materials and designing ideas of the colorimetric and/or fluorescent probes for fluoride ion based on different detection mechanisms in recent years were reviewed. Two main categories including formation of hydrogen bonds and formation of coordination covalent bonds were discussed. The latter one is further subdivided into three types, formation of B-F bond, formation of Si-F bond and formation of Mn+-F bond.

Underwater active polarization descattering based on a single polarized image.

Active polarization imaging techniques have tremendous potential for a variety of underwater applications. However, multiple polarization images as input are necessary for almost all methods, thereby limiting the range of applicable scenarios. In this paper, via taking full advantage of the polarization feature of target reflective light, the cross-polarized backscatter image is reconstructed via introducing an exponential function for the first time, only based on mapping relations of co-polarized image. Compared with rotating the polarizer, the result performs a more uniform and continuous distribution of grayscale. Furthermore, the relationship of degree of polarization (DOP) between the whole scene and backscattered light is established. This leads to an accurate estimation of backscattered noise and high-contrast restored images. Besides, single-input greatly simplifies the experimental process and upgrades efficiency. Experimental results demonstrate the advancement of the proposed method for objects with high polarization under various turbidities.

Influence mechanism of the particle size on underwater active polarization imaging of reflective targets.

Underwater active polarization imaging is a promising imaging method, however, it is ineffective in some scenarios. In this work, the influence of the particle size from isotropic (Rayleigh regime) to forward-scattering on polarization imaging is investigated by both Monte Carlo simulation and quantitative experiments. The results show the non-monotonic law of imaging contrast with the particle size of scatterers. Furthermore, through polarization-tracking program, the polarization evolution of backscattered light and target diffuse light are detailed quantitatively with Poincaré sphere. The findings indicate that the noise light's polarization and intensity scattering field change significantly with the particle size. Based on this, the influence mechanism of the particle size on underwater active polarization imaging of reflective targets is revealed for the first time. Moreover, the adapted principle of scatterer particle scale is also provided for different polarization imaging methods.

Tunable Aggregation-induced Emission and Emission Colors of Imidazolium and Pyridinium Based Hydrazones.

Aggregation-induced emission (AIE) materials have drawn great attention for their wide applications as optical materials. The applications of AIE materials, however, are restricted by the complicated syntheses, hydrophobic properties and short emission wavelengths. Herein, an imidazolium based hydrazone (E)-1-(4-methoxyphenyl)-2-((1-methyl-1H-imidazol-2-yl)methylene)hydrazine hydrochloride (1) and a pyridinium based hydrazone (E)-1-(4-methoxyphenyl)-2-(pyridin-4-ylmethylene)hydrazine hydrochloride (2) have been synthesized. Notably, 1 and 2 in crystals show distinct green and near-infrared (NIR) fluorescence, with emission peaks at 530 and 688 nm, and Stokes shifts of 176 and 308 nm, respectively. After grinding the crystals to powder, the absolute fluorescence quantum yield (ΦF) of 1 is increased from 4.2% to 10.6%, and the ΦF of 2 is increased from 0.2% to 0.7%. X-ray crystallography studies together with theoretical calculations indicate that the enhanced emission of 1 arises from hydrogen bonding induced rigid network, and the fluorescence in the NIR region and large Stokes shift of 2 are attributed to its twisted molecular structure and strong push-pull effect.

Visibility enhancement of underwater images based on polarization common-mode rejection of a highly polarized target signal.

Underwater active polarization imaging is promising due to its effect of significantly descattering. Polarization-difference is commonly used to filter out backscattered noise. However, the polarization common-mode rejection of target signal has rarely been utilized. In this paper, via taking full advantage of this feature of Stokes vectors S2 which ably avoids interference from target light, the spatial variation of the degree of polarization of backscattered light is accurately estimated, and the whole scene intensity distribution of background is reconstructed by Gaussian surface fitting based on least square. Meanwhile, the underwater image quality measure is applied as optimization feedback, through iterative computations, not only sufficiently suppresses backscattered noise but also better highlights the details of the target. Experimental results demonstrate the effectiveness of the proposed method for highly polarized target in strongly scattering water.

Measurement and analysis of the longitudinal level irregularity of the track beam in monorail tour-transit systems.

Notable effects on the vertical dynamic response of vehicle-bridge systems are introduced by longitudinal level irregularity (LLI). However, in monorail systems, the measured data and associated spectrum of the LLI, i.e., the distribution curve of power spectral density versus wavelength, have not been reported in detail. To address this issue, we propose the inclination correction method (ICM) to measure the LLI in monorail tour-transit systems and further estimate and fit the spectral curves for the first time. The measuring principle of ICM is thoroughly described, and ICM is compared with conventional chord-based methods. In addition, the trend components of the measured LLI are eliminated through an adaptive method preceding spectral estimation to avoid potential errors. Notably, a simulation program is designed, and the results from existing methods are adopted to verify the proposed ICM. Based on an analysis of the results, the accuracy and robustness of ICM are demonstrated, and the applicability and advantages of autoregressive models and the proposed fractional functions in spectral analysis are revealed. Finally, combining qualitative and quantitative calculations, an evaluation approach for the generic spectra of monorail LLI is established.

Related Risk Factors between Subclinical Carotid Atherosclerosis and Diabetic Retinopathy in Newly Diagnosed Type 2 Diabetes Mellitus in China.

PURPOSE: To analyze the clinical features and related risk factors in diabetic retinopathy (DR) and subclinical atherosclerosis, the micro- and macro-vascular diseases in newly diagnosed type 2 diabetes mellitus (T2DM). METHODS: A retrospective study of 435 cases of inpatients with newly diagnosed T2DM from 2013-2017, and compare the 2 types of T2DM related vascular complications. RESULTS: The macro- and microvascular complications are not rare at this stage. Subclinical atherosclerosis was found in 251 subjects (57.7%), which was higher than that of DR (13.1%). In addition, some cases of subclinical atherosclerosis co-existed with DR, suggesting that DR was related with subclinical atherosclerosis (r=0.098, P=0.041). Older age showed a significant association with both subclinical atherosclerosis and DR. Single factor analysis indicated that dyslipidemia was the common risk factor in DR and subclinical atherosclerosis. CONCLUSIONS: It should be paid attention to the screening of both DR and subclinical atherosclerosis in each age group of newly diagnosed T2DM. Except for the control of blood glucose, the control of the dyslipidemia is important in the prevention and treatment of the micro- and macro-vascular diseases.

Use of additives in composting informed by experience from agriculture: Effects of nitrogen fertilizer synergists on gaseous nitrogen emissions and corresponding genes (amoA and nirS).

The effects of two nitrogen fertilizer synergists (urease inhibitor, UI; nitrification inhibitor, NI) on NH3 and N2O emissions and the successions of the amoA and nirS genes during composting were assessed. Results showed that the UI and UI + NI treatments reduced NH3 emissions by 26.3% and 24.3%, respectively, and N2O emissions were reduced by 63.9% for UI + NI treatment but were not reduced by UI. The addition of UI and NI significantly reduced the abundance of the nirS gene during thermophilic stage, while significantly increased that of the amoA gene during maturation stage. Crenarchaeota was the principal nitrifying archaeal phylum and was significantly affected by pH. Proteobacteria was the main denitrifying bacterial phylum, whose relative abundance was higher for UI + NI treatment than the other treatments. PICRUSt analysis showed that the addition of UI and NI inhibited enzymatic activity related to N transformation during thermophilic stage while enriching enzymatic activity during maturation phase.

Composting pig manure and sawdust with urease inhibitor: succession of nitrogen functional genes and bacterial community.

Understanding the relationship between nitrogen (N) cycle and N transformation-related functional genes is crucial to reduce N loss during composting process. Urease inhibitor (UI) is widely used to reduce N loss in agriculture. However, the effects of UI on N transformation and related N functional genes during composting have not been well investigated. The goal of this study was to investigate the effects of a urease inhibitor (UI) on N functional genes and bacterial community succession during pig manure composting. Results showed that the addition of UI decreased the ammonium N content during the thermophilic stage and notably increased the total N and nitrite N contents of the final compost. The UI significantly decreased the abundances of amoA, nirS, nirK, and nosZ during the initial composting stage, while the opposite trend was observed at the maturation stage. Bacterial community richness and diversity were increased after the UI amendment, but the relative abundance of the phyla Firmicutes and Proteobacteria significantly decreased compared with control during the thermophilic stage. Redundancy analysis indicated that the evaluated environmental factors and bacterial community showed a cumulative 94.7% contribution to the total variation in N functional genes. In summary, UI addition is a recommended method for N conservation during composting, but the added forms of UI, such as delayed addition, combined with adsorbing materials, or microorganism inoculant, should be further evaluated.

Association of diabetic nephropathy with the severity of obstructive sleep apnea-hypopnea syndrome in patients with type 2 diabetes mellitus.

This study aimed to analyze the effect of the severity of obstructive sleep apnea-hypopnea syndrome (OSAHS) on diabetic nephropathy (DN) in patients with type 2 diabetes mellitus (T2DM). A total of 322 patients with T2DM participated in this cross-sectional study. OSAHS was diagnosed according to the apnea-hypopnea index (AHI) and it was categorized as follows: normal, mild, moderate, and severe. Relevant clinical data retrieved from medical charts were cross-analyzed between different groups. The relationship between urinary albumin/creatinine ratio(UACR) and OSAHS parameters, which included AHI, lowest oxygen saturation (L-SaO2), and mean oxygen saturation (M-SaO2), was evaluated by partial correlation analysis. DN stages were classified into a non-DN group, a microalbuminuria group, and a macroalbuminuria group. Multiple factor logistic regression analysis was employed to analyze factors influencing DN. The results showed that mild OSAHS, moderate OSAHS, and severe OSAHS patients had a higher Body mass index (BMI), creatinine (CR) level, UACR, and a longer duration of T2DM (p < 0.05) than the non-OSAHS group. The prevalence of DN in the non-OSAHS, mild OSAHS, moderate OSAHS, and severe OSAHS groups was 18.4%, 19.2%, 34.6%, and 49.4%, respectively (p < 0.05). Multiple factor logistic regression analysis revealed that systolic blood pressure (SBP) (OR = 1.03), AHI (OR = 1.02), and duration of T2DM (OR = 1.04) were correlated with DN (p < 0.05). These findings revealed that OSAHS is highly prevalent in T2DM and AHI is independently associated with the presence of DN.

A novel probe based on rhodamine 101 spirolactam and 2-(2'-hydroxy-5'-methylphenyl)benzothiazole moieties for three-in-one detection of paramagnetic Cu2+, Co2+ and Ni2.

A novel probe based on rhodamine 101 spirolactam and 2-(2'-hydroxy-5'-methylphenyl)benzothiazole moieties (probe 1) was developed as a three-in-one platform for detection of paramagnetic Cu2+, Co2+ and Ni2+ through different processes. Ratiometric changes in emission intensities at 565 nm and 460 nm for 1 (λex = 350 nm) were observed in presence of Co2+, Cu2+ and Ni2+ respectively. This probe displayed ratiometric colorimetric responses and 'turn-on' fluorescence responses (λex = 540 nm) toward Cu2+ and Co2+. Whereas probe 1 exhibited very weak absorption around 480 nm, no 'turn-on' emission (λex = 540 nm) in presence of Ni2+. The detection limits were 0.11 µM and 0.17 µM for Cu2+ and Co2+ ions respectively from ratiometric colorimetric measurements and 26 nM, 54 nM and 101 nM for Cu2+, Co2+ and Ni2+ respectively from ratiometric fluorometric measurements. The excited-state intramolecular proton transfer (ESIPT)-prohibited coupled ring-open process for 1-Cu2+ (1-Co2+) and ESIPT-prohibited irreversible process for 1-Ni2+ were proposed according to the spectral results. Furthermore, probe 1 was utilized to determine Cu2+ and Co2+ in real-life samples with good recoveries.

Modulation of IGF1R Signaling Pathway by GIGYF1 in High Glucose-Induced SHSY-5Y Cells.

Grb10 (growth factor receptor-bound protein 10)-interacting GYF protein 1 (GIGYF1) can modulate insulin-like growth factor 1 receptor (IGF1R) signaling pathway, which plays an important role in regulating diabetes-associated cognitive impairment, by linking to Grb10 adapter. However, it remains unclear whether endogenous GIGYF1 expression is associated with the development of diabetes-related cognitive impairment. In this study, we measured the expression level of GIGYF1, Grb10, phosphorylated IGF1R/IGF1R, phosphorylated AKT serine/threonine protein kinase/protein kinase B (AKT)/AKT, and phosphorylated extracellular signal-regulated kinase (ERK)/ERK in human neuroblastoma SHSY-5Y cells. Meanwhile, we detected cell apoptosis, proliferation, and migration. Our results showed that the percentage of apoptotic cells increased along with the increasing concentrations of glucose (0-200 mM). The expression of GIGYF1 had a significant increase in the presence of 25 mM concentration of glucose in SHSY-5Y cells. In addition, high glucose augmented the expression of IGF1R and Grb10, but decreased the expression of p-IGF1R, p-AKT, and p-ERK. However, GIGYF1 knockdown reversed the decline in the expression of p-IGF1R, p-AKT, and p-ERK. In addition, knocking down GIGYF1 promoted the proliferation and migration of SHSY-5Y cells, but inhibited the apoptosis in SHSY-5Y cells. These results demonstrate that the expression of GIGYF1 can regulate IGF1R signaling pathway in high glucose-induced SHSY-5Y cells.

Early Assessment of the Risk Factors for Diabetic Retinopathy Can Reduce the Risk of Peripheral Arterial and Cardiovascular Diseases in Type 2 Diabetes.

BACKGROUNDS: There is still a lack of consensus about how to assess the risk of peripheral arterial disease (PAD) and cardiovascular disease (CVD) in patients with diabetic retinopathy (DR). AIMS: We investigated the risk factors for DR and their association with PAD and CVD in patients with type 2 diabetes (T2D). METHODS: A total of 1,421 patients diagnosed with T2D participated in this study. DR stages were classified as non-DR, nonproliferative DR (NPDR), or proliferative DR (PDR). Logistic regression analysis was employed to analyze risk factors associated with DR. RESULTS: NPDR and PDR patients had higher systolic blood pressure (SBP) and higher levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) than the non-DR group (p < 0.05). The prevalence of abnormal ankle-brachial index (ABI) in the non-DR, NPDR, and PDR groups was 7.00, 10.80, and 13.96%, respectively (p < 0.05) and the prevalence of peripheral arterial plaques was 68.48, 81.38, and 80.56%, respectively (p < 0.001). Logistic regression analysis showed that DR (vs. non-DR) was associated with peripheral arterial plaques (OR = 2.07), SBP ≥130 mm Hg (OR = 1.53) and levels of hemoglobin (Hb)A1c (OR = 2.11) and TC (OR = 1.42). CONCLUSION: PAD is commonly associated with NPDR and PDR. Hypercholesterolemia is an important risk factor for the development of PAD and CVD in patients with DR. Our results suggest that a routine ABI test, duplex ultrasonography, and obtaining a lipid profile for DR patients may help to reduce the occurrence of PAD and CVD.

A near-Infrared Fluorescent Chemodosimeter for Ratiometric Detecting Fluoride Based on Desilylation Reaction.

A new chemodosimeter based on dicyanomethylene-4H-chromene chromophore (probe 1) was developed as a ratiometric fluorescent probe in near-infrared range for F(-) with good selectivity in acetonitrile. Probe 1 could be used to directly visualize F(-) by the naked eye and showed more than 621-fold fluorescence enhancement at 715 nm upon reaction with F(-) upon excitation at 625 nm. The recognition of probe 1 to fluoride was featured by F(-)-induced red-shifts of both absorption (185 nm) and fluorescence peaks (132 nm) based on internal charge transfer (ICT) in acetonitrile. The desilylation reaction of 1 by F(-) was proposed for its dual absorption and emission ratiometric detection of fluoride.

A dansyl-rhodamine ratiometric fluorescent probe for Hg2+ based on FRET mechanism.

Based on resonance energy transfer (FRET) from dansyl to rhodamine 101, a new fluorescent probe (compound 1) containing rhodamine 101 and a dansyl unit was synthesized for detecting Hg(2+) through ratiometric sensing in DMSO aqueous solutions. This probe shows a fast, reversible and selective response toward Hg(2+) in a wide pH range. Hg(2+) induced ring-opening reactions of the spirolactam rhodamine moiety of 1, leading to the formation of fluorescent derivatives that can serve as the FRET acceptors. Very large stokes shift (220 nm) was observed in this case. About 97-fold increase in fluorescence intensity ratio was observed upon its binding with Hg(2+).

A Novel Ratiometric Fluorescent Mercury Probe Based on Deprotonation-ICT Mechanism.

A new NBD-rhodamine dye (1) was developed as a colorimetric and ratiometric fluorescent chemosensor for Hg(2+) with good selectivity in aqueous ethanol solutions under neutral to basic conditions. Sensor 1 showed absorption at 468 nm and a weak emission at 529 nm (ϕ F = 0.063) in ethanol/aqueous tris buffer (9:1, v/v) of pH 9.17 solution. Bathochromic shifts in both absorption (492 nm) and fluorescence spectra (569 nm, ϕ F = 0.129), respectively upon addition of 2 equiv. of Hg(2+) were observed. The ring-opening reaction of the spirolactam form to the corresponding xanthene form was not found. The interaction of Hg(2+) with chemosensor 1 resulted in the deprotonation of the secondary amine conjugated to the NBD component so that the electron-donating ability of the N atom was enhanced. Deprotonation-ICT mechanism of secondary amines was suggested for the ratiometric fluorescent chemosensing for Hg(2+).

A novel colorimetric and fluorescent "off-on" chemosensor for Cu2+ based on a rhodamine derivative bearing naphthyridine group.

A new rhodamine-based derivative bearing a naphthyridine group (compound 1) was synthesized as a colorimetric and fluorescent "off-on" chemosensor for Cu(2+) in aqueous solutions. The sensing behaviors of 1 toward various metal ions in neutral aqueous solutions were investigated by absorption and fluorescence spectroscopies. Compound 1 is found to exhibit a significant increase in absorbance at 561 nm and an amplified fluorescence at 590 nm toward Cu(2+) in a selective, sensitive and rapid manner. The quantification of Cu(2+) by 1 using an absorption spectroscopy method was satisfactory in the linear working range 0.9-10 µM, with a detection limit of 5.4 × 10(-8) M for Cu(2+) and good tolerance of other metal ions. Upon addition of Cu(2+), the spirolactam ring (colorless and nonfluorescent) of 1 was opened to ring-opened amide (red color and fluorescent) and a 1:1 stoichiochemetry for the 1-Cu(2+) complex was formed with an association constant of 1.57 × 10(4) M(-1).

Excited-state absorption in a terpyridyl platinum(II) pentynyl complex.

The singlet excited-state lifetime of a terpyridyl platinum(II) pentynyl complex was determined to be 268+/-87 ps by fitting femtosecond transient absorption data, the triplet excited-state lifetime was found to be 62 ns by fitting nanosecond transient absorption decay data, and the triplet quantum yield was measured to be 0.16. A ground-state absorption cross section of 2.5 x 10(-19) cm(2) at 532 nm was deduced from UV-vis absorption data. Excited-state absorption cross sections of 3.5 x 10(-17) cm(2) (singlet) and 4.5 x 10(-17) cm(2) (triplet) were obtained by using a five-level dynamic model to fit open-aperture Z scans at picosecond and nanosecond pulse widths and a variety of pulse energies.